All infos about these common in Poland vehicles are very welcome. Since I was never sure how it was with them and surprisingly I couldn't find anything about their history here. For sure there were some Coles imported /vehicle_119416-Coles-Hydra-35-40-T.html , the cabine of this one is also of Coles style. How it was? Everything was made here on licence (interesitng similarity of names Hydros and Hydra)? The Polish cranes (of HSW) were assembled on imported British chassis?

Here is some info finally: http://elbex.com.pl/ They say HSW signed agreement with Coles in 1971. At the back is indeed written 321.
Good we back to this after so many years. Perhaps the reason was, that the episode with this crane was today in TV?
We have also such one: /vehicle_77718-Coles-Hydra-T-300-Series.html Which clearly has British design of the cab. Let's wait with changes in its case. Cranes with this cabs (notable windows) also in Poland are to find under the make Coles, and as usually in those times the agreement was perhaps not only for the production, but also for the import of some vehicles (vide Berliet, Steyr).